Line Out vs Monitor Out: What’s the Difference? (Solved!)

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Line Out and Monitor Out are two audio output ports found on audio devices, especially professional audio gear. However, not many people know the difference between the two. If you are one of those people, then this article is for you.

That’s because, in this article, we’ll cover the difference between Line Out and Monitor Out, and when to choose one over the other. If this is something you’re interested in learning about, then let’s dive into it.

What is Line Out?

Line out refers to any audio output that is built to deliver line-level signals between audio devices. Many audio devices have line outs on them. Some of these audio devices include mixers, keyboards, preamps, synths, guitar amps, and more. This output port delivers clean and pure audio signals.

Line outs are meant for connections to external amplifiers. They can be routed directly to amplifiers. Thus, they do not have amplifiers built into them. Line outs can be used to connect different pairs of studio monitors to your audio interface. It is also useful during mixing. This output can be used to transmit specific kinds of mixes.

Most line out ports is built such that they accept either quarter-inch connectors or XLR connectors.     

What is Monitor Out?

Monitor out is output to your monitor system. It helps you to adjust the level of the audio that goes into your monitors. Monitor outputs are usually found in audio devices such as audio interfaces, AV receivers, and mixer boards. On audio interfaces, they are labeled as either main out or monitor.

A monitor out usually comprises Right and Left audio channels. These channels help you know which line is supposed to be connected to the right and left speakers. Most monitor outs come with 1/4″ outputs. Which means they accept 1/4″ connector pins. 

I have an article on 1/4″ connectors so do well to check it out. Though most monitor outs come with 1/4″ outputs, others come with RCA outputs

What this means is that monitor outs may be compatible with quarter-inch connectors or RCA outputs while most Monitor outputs are meant for connecting directly to powered studio monitors. 

They can also be connected to an amplifier; which is then connected to passive studio monitors. So basically, monitor outputs feed monitor speakers.

Difference Between Line Out and Monitor Out

There is little difference between a line out and a monitor out. This is because they are both engineered to perform the same type of function. That is, they are both responsible for the transmission of line-level audio signals from audio devices and equipment. However, from my research, these are the differences I came across.

The main difference between a line out and a monitor out is that, traditionally, a monitor out is designed as an output to your monitor system while line outs send signals out from one audio device to another. 

The loudness of audio output from a monitor out is affected by the volume of the audio device. This means, the more you increase the volume on the device that has the monitor out, the louder the audio from the monitor output ports becomes as well. On the other hand, line out usually have a fixed loudness

Another difference between these two output ports is the type of audio devices they are found on. As you already know, both line-outs and monitor-outs can be found on mixers and some audio interfaces. However, most of the audio devices that have lineouts are musical instruments. 

Some of these devices include keyboards, digital pianos among others. These musical instruments do not have monitor outs on them. Therefore, lineouts serve as the primary channel for musical instruments to transmit their audio signals.

Similarities Between Line Out and Monitor Out

One of the similarities between a line out and a monitor out is that both outputs are not powered. What this means is that line outs and monitor outs do not come with a built-in means of amplification. 

Thus they need to be connected to an external amplifier. Both output ports must be connected to an external amplifier before the audio signal they are transmitting can be played through speakers.

Therefore, a monitor out and a line out can both be connected to an amplifier; which is then connected to passive monitors speakers. But keep in mind that you can plug either a line out monitor out directly into an active speaker. That’s because active speakers have a power amplifier built into them.

Another similarity between line out and monitor out is their signal direction. Line outs and monitor outs send audio signals in the same direction. Both ports are output ports. Therefore, they transmit audio signals out of an audio device.

Some line out ports (particularly those found on mixers) accept XLR connectors, while some monitor out ports accept RCA connectors. However, most of the audio devices and equipment have line outs and monitor outs that accept quarter-inch connectors. 

This means most line output ports and monitor output ports can be connected using the same kind of cable connectors.

Is Monitor Out The Same As Line Out?

Monitor out and line out are not the same but they are similar. Hence people tend to use them interchangeably. Although both monitor and line out deliver line-level audio signals, monitor out is primarily used to send audio to speaker monitors. On the other hand, line out is used to transmit audio from one audio device to another. 

Monitor out and a line out is similar, thus most people and manufacturers tend to treat them like copies of each other. A Monitor out can usually be found in audio devices such as audio interfaces, mixer boards, and AV receivers. Line outs are no different. 

These audio devices transmit line-level signals. Line level signals are not strong enough to drive a speaker without undergoing amplification.

The user manual of most of these audio devices uses the terms “line out” and “monitor out” interchangeably to mean the same thing. This means manufacturers usually treat both ports as being the same. 

A typical example can be found in how audio interfaces are built. The output port of some audio interfaces comes labeled as either monitor out or line out.

Also, a monitor out port is made up of R and L channels. These are connected to the left and right speakers. Though most line outs are made of a single channel, the line outs on audio interfaces and mixers comprise two channels as well.

Can Line Outs Be Used for Monitors?

Line outs can be used for monitors. However, these monitors should be active monitors. This is because active monitors come with in-built power amplifiers which can amplify the line-level signals transmitted by line outputs.

A line out transmits line-level signals. This line-level signal is not strong enough to drive a monitor unless the signal is amplified. What this means is that, for a line-level signal to drive a speaker, the line-level signal must be stepped up into a speaker-level signal.

Unfortunately, line outs are not built to have their own internal means of amplification. Therefore, they are meant to be connected to external amplifiers before they can drive speakers and monitors. As you already know, a monitor is a form of speaker. Therefore, to use a line out to drive monitors, these monitors must have built-in amplification.


A line out is used to send line-level signals from audio devices while a monitor out is primarily meant for the monitor speakers that are used during the mixing of audio at the studio. However, a line out and a monitor out are similar. 

Thus most people tend to treat them as being the same. Audio devices like audio interfaces have their output port labeled as either line out or monitor out. This is because monitor outputs and line outputs are line-level signals. Both outputs cannot drive speakers on their own. Therefore, they are designed to be connected to external amplifiers or active speakers.